A heat gun or blow dryer and dental floss (slightly less abrasive than fishing line should one slip when performing the procedure) has worked well for me. One thing to take into consideration is to check and make sure that the badge being removed doesn't have any protrusions that go through the sheet metal prior to removal. I've see many badges that have alignment holes behind them. It wouldn't be any fun to remove a badge only to find that you need to put it back on to cover alignment holes. WD-40 works quite well at removing any of the remaining double sided tape.
I hate badges! It's great to have a vehicle with no identifiers left on it. It's amazing how many people don't know what you are driving when there's no logo on the vehicle particularly if the vehicle has been customized to some degree.
